Internet traffic is expected to increase nearly threefold over the coming years mainly driven by on-line video content and non-PC devices (“Cisco VNI Forecast and Methodology, 2015-2020”, Cisco White Paper, 1 Jun. 2016). Historically, telecommunications operators and “last-mile” providers (i.e. service providers delivering a final leg of a telecommunications network providing services to end-users or consumers) have been unable to guarantee a required consistent quality for the delivery of emerging content, especially when delivery involved intercontinental links. This challenge has been sought to be addressed by Content Distribution Networks (CDNs) which Content Providers (CPs, such as media companies, television companies and the like) rely upon to deliver their content with strict performance guarantees. Other models in the content delivery market include: last-mile provider plus Global CDN; last-mile provider plus Global CP; and/or last-mile provider's own CDNs which are interconnected or Federated (“Telco CDN interconnection for Global Content Exchange”, ITU Workshop on “Bridging the Standardization Gap”, 30-31 Jul. 2012, Lao People's Democratic Republic, available at: www.itu.int/dms_pub/itu-t/oth/06/5B/T065B00002000 52PPTE.ppt).
In recent years, several use-cases have been envisaged for CDN Interconnection as documented by the Internet Engineering Task Force (IETF) in “Use Cases for Content Delivery Network Interconnection” (Bertrand et al, 2012, available at tools.ietf.org/html/draft-ietf-cdni-use-cases-10). These include regional CDNs interconnecting to deliver content to each other's consumers or global CDNs terminating content to regional CDN, or federations among CDNs with multi-lateral agreements. In the context of CDN-federation, standards are also being developed, such as at the IETF, that enable interconnected CDNs to request pre-positioning of content within their own boundaries (“Content Delivery Network Interconnection (CDNI) Control Interface/Triggers”, Murray R. & Niven-Jenkins, B, IETF RFC 8007, December 2016, available at datatracker.ietf.org/doc/rfc8007). Content delivery operations driven by CDN-interconnected protocols present a challenge of determining which content should designated for pre-positioning in a CDN (such as a target CDN for local consumer access) and/or which content should be designated for transport to, and/or via, a target CDN only in response to an access request (such as a request for access/retrieval by a content consumer).
Methods for positioning of content (within a collection and/or federation of CDNs) attempt to minimise delivery overhead, such as resource consumption, and improve performance, such as for a consumer, a CDN or the network as a whole. Such approaches focus on content popularity and are frequently based on expert engineers' judgement.
Thus, it would be advantageous to provide for content delivery via multiple interconnected CDNs in which a designation of content for either: transport to a client via one or more CDNs on request; or storage of the content, such as by caching, in a CDN in anticipation of a request, is determined.
An exemplary embodiment of the present invention provides a method for designating a class of data content for delivery via a content delivery network (CDN) to content consumers, the CDN including: an entrance node through which the content enters the CDN; one or more intermediate nodes through which the content traverses the CDN; and one or more edge nodes for delivering the content to the content consumers, and the designation of the content determining how the content will be handled by the CDN as one of: a transport designation by which content is transported from the entrance node to one or more edge nodes; a caching designation by which the content is stored at one or more edge nodes; and a hybrid designation by which content is stored at a node in the CDN for subsequent transport to one or more edge nodes in the CDN, the method comprising: determining a set of one or more transport designation options each identifying a set of nodes and links between nodes for transporting the content from the entrance node to one or more edge nodes for delivery to content consumers; determining a set of one or more caching designation options each identifying a set of edge nodes for storage of the content; determining a set of one or more hybrid designation options each identifying a set of nodes for storage of the content and a set of nodes and links between nodes for transporting the stored content to edge nodes; determining a normalised measure resource requirement for each of the transport, caching and hybrid designation options; and selecting one designation option for the class of content from all of the transport, caching and hybrid designation options by an optimisation function for selecting the designation option based on the determined normalised resource requirement for each option.
A further exemplary embodiment of the present invention provides A computer system including a processor and memory storing computer program code which, when executed, causes the processor to select a designation option of a class of data content, for delivery via a content delivery network (CON) to content consumers, the CDN including: an entrance node through which the content enters the CDN; one or more intermediate nodes through which the content traverses the CDN; and one or more edge nodes for delivering the content to the content consumers, and the designation of the content determining how the content will be handled by the CDN as one of: a transport designation by which content is transported from the entrance node to one or more edge nodes; a caching designation by which the content is stored at one or more edge nodes; and a hybrid designation by which content is stored at a node in the CDN for subsequent transport to one or more edge nodes in the CDN, the selection being performed by the processor carrying out the following steps: determining a set of one or more transport designation options each identifying a set of nodes and links between nodes for transporting the content from the entrance node to one or more edge nodes for delivery to content consumers; determining a set of one or more caching designation options each identifying a set of edge nodes for storage of the content; determining a set of one or more hybrid designation options each identifying a set of nodes for storage of the content and a set of nodes and links between nodes for transporting the stored content to edge nodes; determining a normalised measure resource requirement for each of the transport, caching and hybrid designation options; and selecting one designation option for the class of content from all of the transport, caching and hybrid designation options by an optimisation function for selecting the designation option based on the determined normalised resource requirement for each option.
A further exemplary embodiment of the present invention provides a computer program element comprising computer program code to, when loaded into a computer system having a processor and executed thereon, causes the processor to select a designation option of a class of data content, for delivery via a content delivery network (CD N) to content consumers, the CDN including: an entrance node through which the content enters the CDN; one or more intermediate nodes through which the content traverses the CDN; and one or more edge nodes for delivering the content to the content consumers, and the designation of the content determining how the content will be handled by the CDN as one of: a transport designation by which content is transported from the entrance node to one or more edge nodes; a caching designation by which the content is stored at one or more edge nodes; and a hybrid designation by which content is stored at a node in the CDN for subsequent transport to one or more edge nodes in the CDN, the computer program code causing the processor to perform the selection by carrying out the following steps: determining a set of one or more transport designation options each identifying a set of nodes and links between nodes for transporting the content from the entrance node to one or more edge nodes for delivery to content consumers; determining a set of one or more caching designation options each identifying a set of edge nodes for storage of the content; determining a set of one or more hybrid designation options each identifying a set of nodes for storage of the content and a set of nodes and links between nodes for transporting the stored content to edge nodes; determining a normalised measure resource requirement for each of the transport, caching and hybrid designation options; and selecting one designation option for the class of content from all of the transport, caching and hybrid designation options by an optimisation function for selecting the designation option based on the determined normalised resource requirement for each option.